[PATCH] D42385: [InstSimplify] (X * Y) / Y --> X for relaxed floating-point ops

[Noel Grandin via Phabricator via llvm-commits]

grandinj added inline comments.


================
Comment at: lib/Analysis/InstructionSimplify.cpp:4300
+    if (FMF.allowReassoc() && match(Op0, m_c_FMul(m_Value(X), m_Specific(Op1))))
+      return X;
+
----------------
for these kinds of identities, should we not be matching

      (X * A * B * ....) / X

?

i.e. whereever we are searching inside a group, we should scan until we hit a non-associative operator or an operator of different precedence ?



https://reviews.llvm.org/D42385